There were no clinically relevant events or hospitalizations during follow-up, other than the serious adverse events that occurred during PR therapy. None of the patients died. Mean ALT levels (IU/L) at follow-up Volasertib solubility dmso were lower compared to baseline in patients who achieved SVR, respectively 50 at baseline versus 24 at end-of-follow-up (p = 0.03). Mean ALT levels were comparable between baseline and end-of-follow-up among patients who did not achieve SVR with PR therapy or did not start PR therapy, respectively 78 versus 67 (p = 0.45) and 101 versus 100 (p = 0.97). Median

APRI score of patients treated with miravirsen was comparable between baseline and follow-up, respectively 0.34 versus 0.32 (p = 0.97). There was no significant difference between baseline and end-of-follow-up median APRI score in patients who achieved SVR, respectively 0.32 versus 0.15 (p = 0.11), or in patients who did not achieve SVR, respectively 0.44 versus 0.48 (p = 0.57). Here PI3K inhibitor we present the results of the first study to assess long-term safety of miR-targeted therapy in humans. Up to 35 months following therapy no long-term safety problems were observed among the 27 chronic hepatitis C patients that were treated with miravirsen. None of the patients treated with anti-miR-122 developed HCC or cirrhosis related morbidity such as ascites or variceal bleeding. In addition, antiviral therapy with PR following miravirsen

resulted in SVR in 58% of HCV genotype 1, treatment-naïve patients. MiR-122 is believed to have a tumor suppressive role and has been related to the development of HCC. In vitro studies showed that miR-122 levels were reduced in human HCC cells compared to normal hepatocytes, and that restoration of miR-122 in HCC cells reversed their malignant phenotype and tumorigenic properties (Bai et al., 2009 and Coulouarn et al., 2009). Short-term inhibition of miR-122 using antisense oligonucleotides for

5 weeks was well ID-8 tolerated in adult mice, and these mice did not develop HCC (Esau et al., 2006). In an obesity mouse model induced by a high fat diet, miR-122 inhibition led to a reduction of steatosis (Esau et al., 2006). In contrast, mice lacking the gene encoding for miR-122 developed microsteatosis and inflammation of the liver that progressed to steatohepatitis and HCC later on in life (Hsu et al., 2012 and Tsai et al., 2012). It was postulated that hepatocarcinogenesis was initiated by activation of several oncogenic pathways and the production of pro-tumorigenic cytokines (Hsu et al., 2012). However, the biological and clinical effect of transient inhibition of miR-122 and the subsequent long-term risk for HCC development in humans is still unknown and should be carefully studied in future studies with miR-122 inhibiting agents. It was demonstrated that elevated serum miR-122 level is a sensitive marker for inflammatory activity in the liver and strongly correlates with serum ALT activity (Bihrer et al.